Device for utilizing the off gases from blast-furnaces for preheating the blast.



I J. E. PREGARDIEN, DEVICE FOR UTIL ZING THE OFF-GASES FROM BLAST FURNACES FOR PREHEATLNG THE BLAST.

APPLICATION FILED SEPT.19, 1912,

I Patented July 28, 1914,

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' UNITED; STATES JOSEPH n'rmimr. rnnenamnn. or coLocrim, annular, ass c'non. T0 FRITZ.

' NEUMANN, or AACHEN, GERMANY- DEVICE son UTILIZING THE err case's raom BLAST-FURISIAGES' ron rimannrrufd man anese.

Specification of Letters Patent. t

Original application filed September 10, 1908; Serial No.- 52,511. Divided and. this application filed September 19, 1912.. Serial No. 721,235. a

To all whom it may concern v Be it known that I, J OSEPH ETIENNE Pair GARDIEN, a subject of the King of Belgium, and residing at Cologne, Germany, have invented anew and. useful Device for Utilizing the Off Grasesfrom Blast-Furnaces for Preheating the Blast; and I do hereby declare the following to be a full, clear, and exact description of the same.

This invention relates to a device for reheating the air to be utilized in blast ur naces.

An object of the invention is to provide a device wherein the heat energy of the waste gases from the furnace is utilized for raising the temperature of the incoming air.

Another object of the invention is to provide a device for raising the temperature of the incoming blast prior to the entrance of said blast into other preheating devices.

Another object of the invention is to provide means for utilizing the heat energy of the waste gases after the said gases have served for raising the temperature of the blast prior to the entrance of the blast into the furnace.

Another object of the invention is to provide a device for utilizing the heat energy of the waste gases by means ofradiation or direct transmission of the energy to the cold blast without requiring means in which this heat energy remaining in the waste gases is utilized for raising the temperature of any other heat transmitting medium like water or the like.

A method for utilizing the heat energy remaining in the waste gases after the same have been utilized primarily for heating t blast is described in my co-pending application for United States Letters Patent, Se-

, rial No. 452511, filed September 10th, 1908,

and of which the present application is a divi.ional.

The invention will be described with reference to the accompanyin following specification an the novel features of the same will be more clearly pointed out in the appended claim.

The drawing shows a diagrammatic view of the improved device.

The blast to the furnace a is supplied by theblowers or air compressors b, the disdrawing in the charge pipes of which are connected to the feeder 0. This feeder leads from the bloweI-s to a manifold f from which valve con trolled branch; pipes extend. into a plurality of preheating form of Cowpers or other well known heating devices. The of iron or the may be constructed of me.-

like. a very high degree'in' vices is conveyed into a is connected with, the circular pipe 6 sur these preheating deters the furnace from this circular pipe through a plurality. of nozzles indicated at k.

The pre eating devices 9 are heated by the Waste gases from the furnace, said wastegasesflowmg through the conduit 1 into a. manifold which is connected by a plurality of valve controlled branch pipes with the Cowpers or Experience has shown that the waste ases after having-been utilized in these pre eatblast still possess considerable The heat energy of the offgases from the preheating devices is utilized in the resent invention to heat directly the cold air prior to the entrance of the same into the preheating devices.

The preheating waste gases into a manifold indicated at e and in connection with the smoke-stack or chimney m; into the manifold e or in the conduit which connects the manifold with the smoke-stack and the cold air from the blowers is conveyed into this heat exchange device so as to pass through said device in a direction opposite to the direction in which the waste gases from the preheating devices. flow therethrough.

It may be seen the incoming heat energy.

from the drawing that-the exchange device d is provided with a valve 11, and a similar posed in a bypass which connects the feeder c with the inlet manifold'f for the preheating devices. either be conveyed through the heat "exchange device 03 when the valves n are in the Patented July 28,1914.

sonny in the orm' of'checker work or them The air after having been heated.to-

manifold 72. which rounding the furnace. The heated wind ening devices for raising the temperature of devices discharge the A heat exchange device is built devices preferably in the latter may either be built conduit leading from the feederc to the heat valve n is also inter- The cold air therefore mayheating devices in position shown in the drawing, or the cold air may be conveyed directly into the manifold f.

The heat exchange device 03 preferably is made of iron so as to conduct the heat still rema ning in the waste gases from the precold air coming from the feeder 0.- As indicated in the drawing this air enters the heat exchange device at one end while the waste gases pass through the same end, so that the air is exposed during a relatively long time to the influence of the heat still remaining in the waste gases.

In the present practice the blast prior to a very efficient way to the the entrance into the furnace is heated to a I temperature of approximately 800 cent-irades. The waste 'ases from the furnace are intermittently conducted to the various preheating devices or in other words during certain, periods certain of these preheating devices receive the waste gases and store the same while the cold blast is'heated in some of the other devices which have been heated in one of the previous periods. On account of the high temperature required for the blast of the furnace it was necessary to connect each furnace with a plurality of these preheating devices so as to render it possible to heat the same during a relatively long period. Each of the preheating devices therefore was used for heating the blast in relatively long intervals only, while the periods in which the preheating device acted upon the blast were relatively short.

In the subject matter of the present invention the ofigases from the preheating devices act upon the incoming blast directly so that the air enters the preheating devices at a temperature of approximately 200 centigradcs and the preheating device therefore must only raise this temperature 600 centigrades. It is obvious that less time is required to store in the preheating de ice waste gases adapt-ed to cause an increase of from the other I .600 centigra'des only and it is also obvious that under these conditions a smaller number of preheating devices will be suflicient to perform the'sanie function as a larger number of preheating devices previously used.

I claim:

In combination with ers for supplying air to the furnace, preheating devices for the air connected with the furnace, a heat exchange apparatus built into the discharge from said preheating devices, a conduit connecting the blowers with said 'heat exchange apparatus, a bypass connect-- ing the blowers with the preheating devices directly-and valves in said conduit and bypass.

' In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOSEPH ETIENNE PREGARDIEN.

a blast furnace blow-. 

